Posted on 04/29/2012 11:01:35 PM PDT by DallasBiff
LONDON, April 29 (Reuters) - Large wind farms might have a warming effect on the local climate, research in the United States showed on Sunday, casting a shadow over the long-term sustainability of wind power.
Carbon dioxide and other greenhouse gases from burning fossil fuels contribute to global warming, which could lead to the melting of glaciers, sea level rise, ocean acidification, crop failure and other devastating effects, scientists say.
In a move to cut such emissions, many nations are moving towards cleaner energy sources such as wind power.
The world's wind farms last year had the capacity to produce 238 gigawatt of electricity at any one time. That was a 21 percent rise on 2010 and capacity is expected to reach nearly 500 gigawatt by the end of 2016 as more, and bigger, farms spring up, according to the Global Wind Energy Council.
Researchers at the State University of New York at Albany analysed the satellite data of areas around large wind farms in Texas, where four of the world's largest farms are located, over the period 2003 to 2011.
The results, published in the journal Nature Climate Change, showed a warming trend of up to 0.72 degrees Celsius per decade in areas over the farms, compared with nearby regions without the farms.
"We attribute this warming primarily to wind farms," the study said. The temperature change could be due to the effects of the energy expelled by farms and the movement and turbulence generated by turbine rotors, it said.
"These changes, if spatially large enough, may have noticeable impacts on local to regional weather and climate," the authors said.
(Excerpt) Read more at reuters.com ...
Is electrical energy produced? yes or no
Where does that energy come from? give your answer
If your answer is “from the moving air” then what is the difference between the air before going through the turbine and after it comes out of the turbine?
Momentum is reduced, not temperature.
If you won’t accept the difference between potential energy, and absolute energy values, or that velocity is only a relative measurement, not an absolute measurement like tenperature, then I cannot explain it to you.
Velocity is similar to potential energy in height with gravity. If I raise a rock above the ground, I have supplied potential energy. But I did not raise the temperature of the rock by lifting, nor will it cool as it crutches what it lands upon.
Velocity is the same way. It has no measurement accept in creation to something else. Temperature is an absolute value and needs no reference frame. Think of throwing a ball or throwing a ball from a moving truck and the again thrown inside a moving truck. You cannot relate the velocity to the object’s tempature.
nor will it cool as it crushes what it lands...
Velocity is the same way. It has no measurement accept in relation to something else.
“won’t accept the difference”
Of course velocity is relative, and temperature has an absolute zero but in thermodynamics it’s differences in temperature that you deal with.
Now answer the questions I posed. Here are the first two:
Is electrical energy produced by the turbine?
Where does that energy come from?
Say as much as you want but make sure you answer the questions.
Yes electrical energy is produced by the transfer of momentum of the air to the rotational force on the turbine.
The only effects on temperature are the friction of the moving surfaces and the inefficiencies of the wind turbine equipment. Both of these produce heat.
There is no drop in temperature.
I have been referring to the energy in the moving mass as potential energy in relation to the still frame of reference of the windmill.
A better term is kinetic energy. Momentum is the mass times the velocity. Work is the mass times acceleration (deceleration of the wind mass). Kinetic energy is 1/2 the mass times the velocity squared.
When the wind strikes the turbine blades, the momentum of the collision must remain the same. In reality it is less of a collision and more of a sliding pull. But the result is a slight slowing of the air flow. Momentum is transferred from the air to the rotating blades. The slowing of the wind is a reduction of the air’s kinetic energy. This kinetic energy is the source electrical power transferred through the blades, rotor and generator. Each of those devices have some degree of inefficiency and each one generates heat due to the inefficiencies like friction.
There is no cooling, only heating and transfer of kinetic energy to electrical energy.
Forget momentum. Collisions don’t have momentum. The sum of the momentums of two particles that elastically collide remains the same after the collision. Nothing about energy here.
The energy of each molecule is proportional to the square of its velocity. Slow it down and it gives up energy, and the law of conservation of energy says the energy goes somewhere.
In a gas, molecular motion is its energy. The energy is felt as wind and heat. Wind is a net motion in some direction. Heat is random motion.
In our discussions we’re talking about a gas that’s at a constant pressure.
I am sorry but are simply making things up and ignoring basic physics. This has become a conversation of you claiming red is really blue.
I don’t care to find new ways to explain the same thing over and over.
Have a nice day.
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